JPS6322217A - Encrust wire made of cubic system boron nitride and manufacture thereof - Google Patents

Abstract

PURPOSE:To provide a wire to which CBN is firmly bonded, by charging the mixture of metal powder and cubic boron powder in a gap between a metal pipe and a metal rod inserted in the center part of the metal pipe, and by subjecting the pipe and the rod to heat treatment, cold drawing, polishing and pickling. CONSTITUTION:The mixture obtained by CBN particles having an averaged particle size of 150mum into pure Ni powder at a volume ratio of 13% is charged into a gap between a metal pipe and a metal rod having an outer diameter of 12mm and inserted into the metal pipe. Further the metal pipe is heated after it is welded to be sealed at both ends thereof, and then is subjected to four time repetitions of atmospheric cooling and cold-drawing to be reduced down to 1mm diameter. The above-mentioned process is one practical example in which charged Ni is metallically bonded to form a layer firmly carrying CBN particles. Thereafter, thus obtained product is dipped in a solution of hydrochloric acid to remove the part of the metal pipe at the outer peripheral section of the product. This CBN encrust wire may facilitate the cutting and grinding of iron group materials, and the cutting speed may be made to be high while the life of the CBN encrust wire is prolonged.

Description

[Detailed Description of the Invention] <Industrial Application Field> This invention is characterized by the fact that cubic boron nitride (hereinafter referred to as carbon
BN (Cubic 13oron N1tride
) is characterized in that the particles are in close contact with each other.
The present invention relates to a BN incrust wire and a method for manufacturing the same.

<Conventional technology> In recent years, wires have been used for cutting ceramic and cemented carbide materials, cutting semiconductor materials such as silicon and gallium arsenide, and chamfering metal workpieces with very narrow holes. being considered or implemented.

<Problems to be solved by the invention> For this reason, extremely strong high tensile strength wires, so-called saw wires, have been used as wires, but
In this case, since the cutting is performed only by friction between the wire and the material to be cut, there is a problem of poor cutting efficiency.

There is also a method called discharge wire cutting, in which a high voltage is applied between the material to be cut and the wire, and the wire is cut by electrical discharge between them. There is a problem that the material of the material is limited.

On the other hand, in recent years, a cutting method using a diamond wire whose surface is coated with fine diamond particles by plating has become known.

However, this method only coats the wire surface with diamond grains mainly by 5-plating or NL plating, so the diamond adhesion is weak and it is difficult to uniformly coat the entire wire surface. There was a problem.

In general, when cutting or grinding using diamond, if the workpiece is a ferrous material,
There is a problem that adhesion between diamond and iron tends to occur, making it difficult to process.

Furthermore, as shown in Japanese Patent Application No. 61-2606, a cylindrical metal body with a gap between the outermost periphery and the center is used, and this gap is filled with a mixture of metal powder and CBN particles and sealed. After applying hot processing such as extrusion or rolling to this,
Although there is a method of manufacturing a similar wire rod by performing cold working, this method requires hot working such as extrusion or rolling, and is therefore not economically preferable.

Means for Solving Problems> The present invention, as a result of studies to eliminate the drawbacks of the above-mentioned conventional methods, provides an inexpensive wire in which CBN particles are uniformly and firmly adhered to the surface layer, and a method for manufacturing the same. The purpose is to

That is, this invention first inserts a metal rod into the center of a metal pipe, fills the gap between the pipe and the metal rod with a mixture of metal powder and CBN particles, seals the end, and then inserts the metal rod into the metal pipe. Heat treatment such as annealing or patenting and cold wire drawing are repeated to obtain a wire rod, and then the metal pipe portion that constitutes the outermost surface of the wire rod is removed by polishing, pickling, etc., and the outermost layer is made into metal powder. A CBN incrust wire as a bonded mixed layer with CBN particles and a method for manufacturing the same.

It is.

<Function> In the present invention, carbon steel is generally used as the material for the metal pipe and the metal rod to be inserted, but stainless steel, 5-alloy, etc. may also be used depending on the conditions of use. Furthermore, the metal pipe and the metal rod to be inserted may be made of different materials.

Note that the thickness of the metal pipe, the diameter of the metal rod to be inserted, etc. can be arbitrarily selected depending on the diameter of the final wire used, the particle size of CBN to be filled, and the filling ratio.

Further, as the metal powder to be mixed with the CBN particles, NL powder or NL-based alloy powder is generally used, but in addition to these, metal powder, ferrite-based gold powder, Fe powder, or F8-based alloy powder may also be used. Then, a metal pipe with both ends sealed is repeatedly subjected to heat treatment such as annealing or patenting and cold wire drawing to obtain a wire rod of a desired wire diameter. At this time, if it is undesirable for the metal powder filled by heat treatment to diffuse toward the metal pipe or the inserted metal rod, it is recommended to apply 5-plating, etc. to the inside of the metal pipe or the outside of the inserted metal rod. This can also be prevented by

After that, in the drawn steel wire, by removing the part corresponding to the metal pipe before processing by polishing or pickling, a mixed layer of metal powder and CBN particles appears on the outermost part of the wire. This makes it possible to obtain a CBN-in-crust wire in which CBN is more firmly adhered than the wire produced by the plating method described above.

<Example> Hereinafter, this invention will be explained in detail with reference to Examples.

Example 1 A general structural carbon steel pipe (JIS 5TK30) was used as the metal pipe, and a piano wire rod (JIS 5TK30) was used as the inserted metal rod.
IS 5WR372B> was used.

The gap between this metal pipe and the metal rod inserted therein was filled with a mixture of pure NL powder and CBN particles having an average particle size of 150 μm at a volume ratio of 13%.

The metal pipe at this time had an outer diameter of 20# and a wall thickness of 2 mm, and the inserted metal rod had an outer diameter of 12#.

After filling, both ends of the metal pipe are welded and sealed, and 850
The heat treatment of heating to 'C and then cooling in the atmosphere and cold wire drawing were repeated 4 times, 1. Wire drawing was performed up to Osφ.

At this time, the filled Nj powder was metallically bonded by heat treatment and cold wire drawing to form a layer that firmly supported the CBN particles. The tensile strength at this time is 160kg! Met. This was immersed in a hydrochloric acid solution with a concentration of 35% for 15 minutes to remove the metal pipe portion (STK30) on the outer periphery, and then neutralized and washed with an alkaline solution.

The microstructure of the surface of the wire produced in this manner is as shown in the drawings, as seen in an electron micrograph.

This drawing shows that the wire manufactured by the method of the present invention has CBN uniformly adhered to it and has good cutting power, and that conventional diamond wires do not adhere when cutting and grinding iron-based cable materials. However, it was possible to cut and grind extremely well.

Example 2 A metal pipe and an inserted metal rod made of the same material as used in Example 1 were used, and pure NL powder with an average particle size of 15 was used in the gap between the two.
A mixture containing 15% by volume of μm CBN particles was filled.

The size of the metal pipe at this time is 25M in outer diameter and 2m in wall thickness.
A metal rod with a diameter of 18 m was inserted into this. After welding and sealing both ends, the heat treatment of heating to 850°C, then cooling in the atmosphere, and cold wire drawing were repeated seven times.
．． Wire drawing was performed up to 2Mφ.

The tensile strength at this time was 195KI4J.

This was immersed in a 35% hydrochloric acid solution for 20 minutes, the metal pipe (STK30) on the outer periphery was removed, and then neutralized and washed with an alkaline solution.

A semi-sintered body of WC-12% alloy as a material to be cut was prepared by using the wire produced in this manner and a diamond wire having the same wire diameter obtained by the conventional plating method. m
/sec load 1 K3 1
Cutting with a cut surface of 35 Mφ was carried out under the conditions of K9, and the results shown in Table 1 below were obtained.

Table 1 From the above table, it was found that the wire produced by the method of the present invention has stronger adhesion to CBN molding than the wire produced by the conventional plating method, can increase the cutting speed, and has a significantly longer life.

<Effects of the Invention> As described above, the CBN incrust wire produced by the method of the present invention is easier to cut and grind ferrous materials than the wire produced by the conventional plating method, and can be cut at a faster cutting speed. It has a long life and can be widely used as an extremely excellent cutting and grinding wire, and can also be widely used as a wire for chamfering, etc.

[Brief explanation of the drawing]

The drawing is an electron micrograph with a magnification of about 30 times showing the structure of the wire surface of the present invention. Applicant's agent Patent attorney Kazu 1) 1959 AI4 Procedural amendment

Claims (2)

[Claims] (1) A metal pipe with a metal rod inserted in its center is filled with a mixed powder of metal powder and cubic boron nitride powder, and subjected to heat treatment, cold wire drawing, polishing, and pickling. Cubic boron nitride incrust wire. (2) Insert a metal rod into the center of a metal pipe with one end sealed, fill the gap between the metal rod and the metal pipe with a mixed powder of metal powder and cubic boron nitride powder, and seal the other end. After that, the metal pipe is repeatedly subjected to heat treatment such as annealing or patenting and cold wire drawing to form a wire rod, and then the metal pipe portion that constitutes the outermost surface of the wire rod is removed by polishing, pickling, etc. A method for producing a cubic boron nitride incrust wire, characterized in that the outermost surface layer is a bonded mixed layer of metal powder and cubic boron nitride particles.